Indonesia has put its rescue aircraft and ships to scour the sea north of Bali to hunt for the 44-year old KRI Nanggala-402 submarine that went missing on Wednesday.
Contact with the German-built vessel carrying 53 crew members aboard was lost when it was preparing to conduct a torpedo drill. Oxygen levels in the submarine is expected to run out within 24 hours.
The Navy has said a blackout may have occurred during static diving, causing a loss of control and preventing emergency procedures from being carried out.
The Indonesian Navy has deployed its warship Riguel equipped with a high-tech sonar to locate the missing diesel-electric powered submarine. The Australia, India, Singapore and the U.S. have also lent their support, sending aircraft and warships to increase the search area.
In a press conference Friday, Maj. Gen. Achmad Riad, the head of the military's central information unit, said the Navy found an object with "strong magnetic resonance" at a depth of 50 to 100 meters during the search. It most likely came from KRI Nanggala.
The military suspects an oil spill seen in aerial surveillance near the dive point on Wednesday came from the craft. Adm. Yudo Margono, the chief of staff of the Indonesian Navy, said there are two possibilities to explain the oil spill spotted on the surface: the submarine tank could be leaking because it dove too deep, or the submarine released fluid on board in an attempt to rise to the surface.
The submarine reportedly has the capability to dive up to 500 meters below sea level, but authorities estimate it went 100 meters to 200 meters deeper than that.